1. Field of the Invention
This invention relates generally to hydraulic system accessories, such as cavitation eliminators, pulsation dampeners, shock arrestors, and the like. More particularly, the invention relates to an improved hydraulic system accessory of this class containing a gas filled, hydraulic pressure responsive bladder which is easily removable and replaceable in the field when worn.
2. Discussion of the Prior Art
As will appear from the ensuing description, the improvements of this invention may be utilized to advantage in a variety of hydraulic system accessories of the class described, such as those mentioned above, i.e., cavitation eliminators, pulsation dampeners, shock arrestors, and the like. However, the invention is primarily concerned with, and will be described in the context of, a cavitation eliminator.
As is well known to those versed in the field of hydraulic systems and equipment, cavitation is a problem which is often encountered in a variety of hydraulic systems, and tends to cause damage to certain types of hydraulic machines. For example, many kinds of reciprocating pumps tend to produce cavitation during their suction strokes, and such cavitation tends to damage the pumps and/or their prime movers.
A cavitation eliminator is utilized to avoid this cavitation problem and its adverse consequences. Simply stated, a cavitation eliminator comprises a casing with an inlet for connection to a hydraulic system and containing a flexible gas filled bladder. Under normal operating conditions of the hydraulic system, the hydraulic pressure in the system acts on the bladder to maintain the bladder in a partially collapsed or compressed configuration, wherein the gas pressure within the bladder balances the hydraulic fluid pressure on the outside of the bladder. When cavitation occurs in the hydraulic system, the hydraulic fluid pressure acting on the bladder diminishes. Under these conditions, the pressurized gas within the bladder expands the bladder outwardly, thereby displacing hydraulic fluid from the casing of the cavitation eliminator back into the hydraulic system thereby immediately filling the void produced by cavitation and hence, eliminating cavitation.
A wide variety of such cavitation eliminators have been devised. This invention is concerned with a problem which is frequently encountered in the use of the existing cavitation eliminators. The problem referred to resides in the fact that the bladder of the cavitation eliminator becomes worn and/or otherwise deteriorates over a period of time. As a consequence, it is necessary to periodically either replace the entire cavitation eliminator or replace its bladder. Replacement of the bladder in the existing cavitation eliminators of which I am aware is extremely difficult and time consuming to accomplish for the reason that such bladder removal and replacement requires cutting of the bladder casing to remove the worn bladder and welding of the casing after assembly therein of the new bladder.